In the field of radiology, various devices have been proposed for imaging portions of the human body. For example, magnetic resonance imaging and X-ray devices have been in common use for many years. Specialized mammography X-ray devices have been developed for providing images of breast tissue. Mammography X-ray devices are particularly useful in detecting presence of tumors, microcalcifications, and other abnormalities at an early stage when potentially not yet detectable by touch.
Imaging devices provide output images in various formats, for example via a CRT or printer, or on film. X-ray devices typically provide output in the form of a film that blackens when exposed to X-rays and then developed. Areas of the film exposed to a greater amount of X-ray radiation are blackened more than areas that are exposed to a lesser amount. Different body tissues, bones, etc. block X-ray radiation to differing degrees, and it is the contrast in transmitted radiation impacting the film that provides an image of the exposed body parts.
Exposed X-ray film is typically viewed on an illuminated X-ray viewer that holds the film on a backlit, clear or white surface. Often, the film is mostly black or dark gray, with images appearing in white or light gray. Physicians and mammographers must examine the film very closely to determine whether any small abnormalities such as those mentioned above are present. Very close study of breast X-ray film images is critical, as chances for successful treatment can depend on early detection of tiny abnormalities and corresponding early treatment before the abnormalities grow, multiply, or metastasize. Thus, physicians and mammographers on the lookout for very small features potentially captured by the film often view the brightly illuminated images very closely (within inches of their eyes) or under magnification, or sometimes both. Also, analog or digital images could be displayed on a display element such as a CRT device, rather than on X-ray film. In such situations, a close reading of features in an illuminated image is also required.
The presence of breast implants, whether utilized for reconstructive purposes after surgery such as mastectomy or electively implanted for cosmetic purposes absent such previous surgery, can render reading X-ray images more difficult. For example, breast implants typically block much more radiation than breast tissue. Thus, breast implant images appear almost entirely white or clear on an X-ray viewing device.
Because of the backlighting required to read the X-ray image, and because the studied portion of the image is generally the brighter (whiter) portion of the image, it can be difficult to differentiate between certain features within the X-ray image. Also, viewing such well-lit images may lead to irritation or discomfort simply from having to look closely at illuminated images for an extended period of time.
In situations where implants are present in the images, the bright light passed through the film or displayed on a CRT by the implant portion can render the image even more difficult to properly examine due to the contrast between the bright implant image portions and the typically darker tissue image portions. Also, it can be more difficult to detect abnormalities disposed in tissue adjacent the edges of the implant due to the brightness of the implant image.